<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <link href="https://cdn.bootcss.com/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
    <script src="./js/vue.js"></script>
    <title>Title</title>
</head>
<body>
<div id="app">
    <p v-if="score>90">优秀</p>
    <p v-else-if="score<=90 && score>70">良好</p>
    <p v-else-if="score<=70 && score>60">及格</p>
    <p v-else>不及格</p>
</div>

</body>
<script>
    var vm =new Vue({
        el: "#app",
        data: {
            score:50
        }
    })
</script>
</html>